Spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA) is a rare autosomal recessive hereditary skeletal disease, and mutations in WISP3 are responsible for its onset. WISP3 is essential for maintaining cartilage integrity mainly by regulating the expression of collagen II, and mutations of WISP3 linked to SEDT-PA can compromise this function and lead to cartilage loss, which is frequently misdiagnosed as juvenile idiopathic arthritis. It is characterized by arthralgia, joint contractures, bony swelling of metacarpophalangeal and interphalangeal joints and platyspondyly. Clinical and laboratory signs of joint inflammation such as synovitis, a high erythrocyte sedimentation rate and an elevated C-reactive protein level are usually absent. Although the disease begins early in life (usually between 3 and 8 years of age), the diagnosis may be delayed. In the present case report, we describe a female patient diagnosed with SEDT-PA at the age of 40 years, although she had been exhibiting the typical radiological and clinical features of the disease since the age of 8 years. Genetic disorders like SEDT-PA may also have rheumatological involvement, and thus should be kept in mind in the differential diagnosis of inflammatory joint diseases.